MOD 7 Flashcards
What are infectious diseases?
Are diseases that are caused by a pathogen entering the body and can be transferred from person to person.
What are non-infectious diseases?
Diseases that can cannot be spread from person to person
What is the cause of infectious diseases? (2)
Bacteria
Pathogens
What causes non infectious diseases?(2)
Genetics
Environment factors
What was the past theory of infectious diseases?
Spontaneous generation, which is living organism (fles) could arise from the decay of susbtances (rotten food)
What is the theory now of infectious diseases?
The germ theory of disease, it states that diseases and decay are the product of living organisms,
What Are communicable diseases?
Disease that is transmitted from plant to plant or animal to animal.
What are viruses(3) ?
-Package of DNA/RNA surrounded by proteins
-Extremely small
-Non cellular and therefore non living and can’t grow or reproduce
-Invades host cells -> injects its genetic material into host cell -> cell
-metabolises new viruses
-Can only survive in live cells
-Vaccines are effective in getting rid of viruses
What is bacteria?(3)
-Tiny prokaryotic single cellular
-Non nucleus
-Have cell wall and membrane
-Single strand of DNA
-Reproduce via binary fission
-Invade cells and form colonies and disrupt normal cell function
Can survive in reservoirs
What are fungi?
-can be multicellular or unicellular
-Eukaryotic
-Reproduce asexually via spores
-Has membrane and cell walls
What is protozoa?
-Single celled eukaryotic organisms
-Have cell membrane
-NO cell wall
-Heterotrophs
-Form colonies that disrupt normal cell function
What are Heterotrophs?
Absorbs nutrients from their host
What is Epidemic:?
sudden spike in the prevalence of an infectious disease in a region / community
What is Pandemic?
sudden spike in a disease across the entire world
What is Enzootic?
endemic amongst animals in a particular region
What is the cycle of disease transmission? (6)
1- infectious agent
2- reservoir
3- portal of exit ( respiratory, gastrointestinal, genitourinal, skin)
4- mode of transmission (direct contact, indirect contact, vector transmission)
5- portal of entry
6- susceptible host
What are infectious agents in the cycle, what arethey capable of?
They are pathogens, which are capable of infectious and causing disease, the more virulent a pathogen is, the greater effect it will have on the health of the host.
What is virulent?
The ability of pathogen infecting a host, more virulent more harm
What is a reservoir?
Is where the pathogen normally lives and reproduces
- soil
- water
- faeces
What is the portal of entry and exits of the infectious agent? (4)
- respiratory- includes the mouth and throat, increase mucus production and can exit by coughing and enter vi breathing close to an infected individual
- gastrointestinal- includes the stomach and intestines (both), oral cavity rectum is the portal of exit through diarrhoea and vomiting
- genitourinal- includes the reproductive organs, can be exited via urethra and through sexual contact
- skin- it provides a barrier, when infected the blood can exit the wound and cause transmission and diseases can enter the wound and go into the bloodstream
What is transmission?
Is the way a pathogen spreads diseases from one host to the next
What is direct contact, 2 examples?
Where there is physical contact, between the host and non infected person or reservoir and a infected person
- contact of body fluids with infected person
- touching the person infected
What is indirect contact,2 examples?
When the host and another organism have no direct contact with each other, requires an intermediate between the host as the next, this can be contaminated material,
Contaminated food
Contaminated surgical equipment
What is vector transmission, 2 examples?
It occurs through a transmission agent, such as mosquitoes and flies, where they bite and transmit the disease
- mosquitoes (malaria)
- hendra virus (fruit bats
What is a susceptible host in the cycle?
Organism that will be infected, which depends on genetics, immunity and overall health
What is the cause of ebola, is it RNA or DNA?
Server infectious diseases caused by ebola virus, it’s an single stranded RNA virus
How can ebola be transmitted (3)?
- bodily fluids such as blood from infected person
- contaminated surfaces
- sexual contact
What are the symptoms of ebola(3)?
- Flu like symptoms
- diarrhoea
- internal bleeding
How to manage(as soon as it happens) the outbreak of ebola(3)?
Quarantine
Lockdown
Social distancing
How to control the future outbreaks of ebola(1)?
Vaccines
What are some risk factors (catching) of ebola (2)?
Working in the medical industry —> Exposure to infected objects
Travelling to area with recent outbreaks
What are the steps of making a petri dish?(7)
1- sterilise the bench using alcohol
2- using an inoculating loop put into flames across motion s to sterilise
3- dip the inoculating loop into sample
4- open the petri dish at a 45 degree angle so that the bacteria in the air doesn’t go inside
5-using the inoculating loop in a snake like movement place into the pert dish
6- put upside down so condensation happens and doesn’t go into the sample
7- leave for about 2-3 days in the incubator at 35 de
What is koch’s postulate experiment ?
His experiment involved to take the blood sample of a infected person and then isolated and culture the disease in a petri dish/ agar plate then he would insert it into a healthy person, and observed the symptoms
What was the conclusion of Koch’s postulate experiment?
He concluded that when giving the disease of the infected individual the healthy individual will develop the same symptoms as the infected.
What disease does the koch use for this postulate experiment?
He examined anthrax which had a rod shaped bacteria, used sheeps as a subject.
What were teh2 breakthroughs of Koch’s postulates experiment?
1- discovery of mycobacterium tuberculosis, which cause tuberculosis
2- discovery of a bacterium causes cholera
What was the criteria of koch postulate experiment? (3)
- same organism
- pure culture is injected into healthy host (same symptoms must be presented)
- micro organism must be isolated from the second and third host before injected (same symptoms must be presented)
What are the procedure of
Koch postulates?
1-specific microbe must be present in every host with the disease
2-The specific microorganism must be isolated from the host and grown in a pure culture, on a sterilised agar plate
3-A potential host when inoculated with sample of the Pure culture must develop the same symptoms as the original host
4- The specific microbe must be isolated from the second host and cultured and identified as the same species as originally cultured.
What is pasteurisation?
Heating kills most microbes responsible for spoiling the product
How do we conduct the pasteur’s experiment?(5)
1 - pour in bone broth into 2 conical flasks
2- place swan necks on them both
3- using hot pate we heat the conical flask to sterilise them
4- take one of the swan neck off
5- observe
Why do we use a swan neck?
It allows air to enter but it stops microbes and dirt from entering as they get suck in the
S- shape.
What did Pasteur observe from his broth experiments?
That the broth in the open necked flask became cloudy, indicates there are germs, but the broth in the swan neck was unchanged free of germs.
His experiment demonstrated that microbial germs are airbones, and life cannot be sterilised mediums.
What is the relationship between pasteur and anthrax?
Pasteur investigated the cause of anthrax while Koch’s finding showed that animals were contracting disease if they had been in contact with an infected individual.
How can animals still get infected if not in contact with animals?
animals were contracting disease even if they had no contact as they were grazing on soil which had the disease of the buried infected animals.
What are some symptoms of diseases in plants?(2)
Stunt growth
chlorosis(yellowing on leaf, lacks chlorophyll)
What does innate mean?
Inherited and non specific, part of the first line and second line of defence
What are biotrophs?
This is where a pathogen enters a plant host but doesnt kill, as they depend on tht plant for nutrients